"Redeem" comes from a root word that means to buy or to distribute. In Latin, it came to mean to buy back. The word "ransom" comes from the same root, so in that sense, the word "redeem" is the ransom paid to buy back a captive. At the time John Wycliffe translated the New Testament, the word "redeem" was not in the English language. He translated the concept of redeem as "again  bought" (redeem came into use in the English language around the year 1415).